Kristie Miller – The New Growing Block Theory

Abstract
It was once held to be a virtue of the growing block theory that it combines temporal dynamism with a straightforward account of in virtue of what past-tensed statements are true and an explanation for why some future-tensed statements are not true (assuming they are not). This put the growing block theory ahead of its principal dynamist rival: presentism. Of late, however, defenders of the growing block theory have moved towards a view about past-tensed truthmakers that is inching ever closer to that of the presentist, insofar as what makes true our past-tensed statements is not the same kind of thing as what makes true our present-tensed statements. New growing block theorists have moved to this position to defuse the following objection: given that if our world is a growing block there are very many more past locations than there are present locations, and given that the past is relevantly like the present from a first-person perspective we should think it much more likely that we are located in the past than in the present. Call this the ‘now now’ objection. In response to this objection, defenders of the new growing block theory have sought to distinguish the past from the present not merely metaphysically—in terms of which three-dimensional slices of reality are at the end of the growing block and which are located within the block—but also by their qualitative properties such that it is possible, from the first person perspective, to distinguish the past from the present. This paper considers, first, some different ways in which the new growing block theorist could differentiate the past from the present such that they are introspectively distinguishable. It then considers how these strategies fare in providing truthmakers for past-tensed statements. The paper argues that the new growing block theorist faces a dilemma. The more unified a strategy is for responding to the now now objection, the more that strategy results in the new growing block model positing truthmakers that are similar to those posited by the presentist. Thus the new growing block theorist ends up embracing what I call a shrivelling past: a past that is significantly qualitatively different from the way those past times were, when they were present. Embracing a shrivelling past, however, erodes the purported advantage of the growing block theory over presentism. On the other hand, while versions of the new growing block theory that embrace disunified strategies commit themselves to a past that is somewhat less shrivelled, and are therefore better able to differentiate themselves from presentism, they are, in turn, unattractive because of their disunity.

17 comments

Peter Forrest

Let’s agree to call the problem the now now objection – I’ll stop calling it the Napoleon Problem.

In Kristie’s wonderfully thorough treatment, hypertime versions are discussed in some detail but without much enthusiasm. She considers Hypertemporal Record Truthmaking: past tensed truths are made true by the way the world is, at some earlier moment in hypertime. This is a growing ‘hyperblock’ theory or , more accurately, a growing objective history theory. I say ‘more accurately’ because the ‘hyperblock’ doe not have spatial dimensions

The resort to hypertime solves the now now problem only if we adopt the hyper-presentist thesis that only the hyper-present is real. But to defend hypertime I take it to be true time and the time-like dimension of space-time to be , if you like, hypo-time. Hence I cannot resort to the otherwise attractive position of hyper-presentism.

I defend hypertime by de-coupling the metric from the (totally ordered) ordinal aspects of time. We take the order out of space-time, although its geometry still has a double-cone structure. At each point there are two cones which we can label the f-cone and the p-cone, provided we grant that there is no intrinsic future/past difference between the two partial orderings defined by the cones. So it is as C-theorists (e.g. Huw Price) say except that the t-extent is only potentially infinite. The temporal ordering is then that of the integers. This ordering is so-called hypertime but I take it to be true time with space-time being four dimensional space – but let is keep ‘t’ for the time-like dimension of space-time, hypotime. So the block grows by the addition of layers, which need neither be of uniform thickness nor of constant thickness. This has the advantage of explicating the otherwise puzzling rate of passage of time, which is the rate at which layers are added. Layers may well be of the order of Planck time thickness, but not necessarily exactly Planck time thickness.

Because this is a de-coupling it is not ontologically extravagant. It would be extravagant if we privileged one of the two partial orderings of the C-theoretic block. It would also be ontologically extravagant only if we posited a metric for ordinal time.

One of the advantages of this de-coupling is that we can deal with Zeno’s paradoxes and with supertasks, by insisting that there are only a finite number of times, even if t takes infinitely many values.

A curious corollary is that, for all we know, the block grows at both ends. Maybe the best physical cosmology has the universe collapsing to a Final Crunch = Big Bang and then expanding again. Assuming the Final Crunch = Big Bang is a low entropy state, then we should expect the universe prior to the Big Bang to be like ours but t-reversed. Hence there might be folk 26 billion years ‘ago’ rather like us if we just replace t by -t. They are our hyper-time contemporaries. Apart from what happens at the Final Crunch = Big Bang this scenario is just like a universe that splits at the Big Bang into two similar branches that cannot influence each other, amd with each branch growing. The spatio-temporal distance between us and our counterparts on the other branch is time-like and is the sum of the two distances from the Big Bang and so even if the two universes are only 13 billion years old the distance is a time-like 26 billion years even though we are contemporaries in hypertime.

This advantage holds especially for those naturalists who ponder the question. ‘Why is there still something rather than nothing?’ and posit existential inertia as the answer. That answer only succeeds if time is discrete, otherwise x at t ensures its existence for no longer than t + 1/2 at most, then for t + 3/4, and then t + 7/8 etc, never making it to t + 1.

The reason why we might prefer a growing hyper-block to hyper-presentism is that we want truth-makers not merely for statements about the past but for statements about what might once have still been possible. But that would be another chapter.

Kristie also raises a problem of what the growing blocker should say about God creating a ‘growing block universe with some of the block “already grown”.’ We might call this hyper-omphalism: on the first day, a bit over 6000 years ago, God created 13 billion years of back block. The problem is that this there would be false traces of older human beings and other conscious animals.

This is not a problem for the growing hyperblock theorist who treats all the hyper-past back blocks as real. David Stove once wittily said of Space and Time, ‘Two more necessary things I never hope to see!’ Space-time I take to be contingent, however, but hypertime, the ordinal , true, time is necessary. So God cannot bring into existence a past ‘block’ of hypertime. But there could be an initial (ie. a hyper-initial) state with four dimensions one of which is time-like. (Compare Stephen Hawkings’s scenario of an initial state of four dimensions all of which are space-like.)

There is a solution for other growing-blockers, including hyper-presentists. We discover rather than posit a simultaneity relation that holds between events that come to exist together. If the growth of the block is continuous then events x and y are absolutely simultaneous just in case they were once both on the edge of the block. If as I hold, the block grows by layers of positive thickness, maybe of order of Planck time, then the equivalence classes are about a Planck time thick. Likewise all the events in the hyper-omphalic 13 billion year back block are absolutely simultaneous. Hence the division of the back block into the equivalence classes preserves in fossilized form the way the block grew, distinguishing false traces from genuine ones.

David Taylor

I think this is a variation of the point you’re making about how embracing the skeptical solution undermines the intuitive motivations for the Growing-Block, but it seems to me the Growing Blocker has the following dilemma.

Presumably, one of the main motivations for GBT is based on to the phenomenological appeal to our experience of becoming, which the Growing-Blocker understands as the coming-into-being of entities at the edge of the block, and presumably they want to reject attempts to account for this experience in a Parmenidean universe. But since becoming only occurs at the edge, the past is basically Parmenidean. So either Caesar is having the experience of temporal passage in which case it must be that you can have an experience of becoming that is doesn’t correspond to anything in the world, thus undercutting the phenomenological motivation, or you have to say that since Caesar isn’t at the edge of the block where becoming is taking place, he either lacks conscious experience or at least has no experience of becoming, which would make his experience qualitatively much different than the experience of someone in the present and thus be to embrace the “new” growing block theory.

Kristie

Emily Paul

Thanks very much, Kristie! I was thinking about something that the growing blocker might offer as a “last gasp,” granting what you have said. That is, why can’t she bite the bullet and accept the “shrivelling past?” Whilst it isn’t something that we’ve ever seen, it does seem to be something like how we remember events that were once present -and this could be because the events are shrivelled due to no longer being present. More importantly, the (new) growing blocker can answer the now now objection with this shrivelling past argument, by denying (II) as you say. However, we then have the issue of truthmaking.
Why can’t the growing blocker appeal to an asymmetry with truthmakers for future-tensed propositions in this case, and say that, even though the past is shrivelled, it’s still far more firmly in existence than the future (which does not exist at all). So Caesar in the past really gets to be the truthmaker of Caesar as we talk about him now. Yes, he is part of a shrivelled sausage, but he was once a wholesome one, and we can still agree that this shrivelled existence is far more substantial than if it were not to exist at all, like the yawning nothingness of the future. Could the growing blocker say that it’s THIS that also retains the advantage over presentism in the truthmaking stakes? Or would you say that this is this still not worth the cost of the shrivelling sausage?

Kristie

So as I read Ross Cameron, that is more or less what he thinks. I take the point: you might think that even a shrivelled past is better than no past, and so think that you still have the upper hand over the presentist (and you get the nice asymmetry of past/future). So it’s not a crazy view- it just seems a bit unfortunately located in a middle-ground position with respect to truth making. But, as you point out, maybe for some that middle ground position doesn’t seem so unattractive.

I think a non-shrivelled past is worse than a shrivelled past. It seems natural to me to think of past things as having ‘a retired or emeritus status’ (a coinage of Hugh’s). Past things are intrinsically the same, on my view, as they were when present, but the truthmaking procedure involves taking into account extrinsic properties (like whether the thing is succeeded by nothing).

Emily Paul

Peter Forrest’s comments above are interesting, but I shan’t engage with them here as I plan to read his paper shortly and so will save any comments I have for then. I wish, rather, to pick up on a slightly different issue arising from Kristie’s (also very interesting) paper.

The issue I wish to pick up on is the issue of whether Growing Block theorists can offer a unified approach to truthmaking that does not end up being similar to those posited by presentists (that they cannot is one horn of a dilemma that Kristie poses in her paper). Here I respond to her by arguing that they can.
Firstly, what is it to offer a ‘unified’ account of truthmaking? Kristie says:

“an approach to truthmaking is unified just in case the sorts of truthmakers it posits for present-tensed statements are the same as the sorts of truthmakers it posits for past-tensed statements.” (p10)

Kristie argues that Growing Blockers cannot offer such an account. She starts by considering a principle from Cameron (2015):

Past Record (PR): If something was the case, then it is the case in the past.

This is supposed to be read as a universally quantified claim, and given the (anaphoric) occurrence of ‘it’ in the consequent, I take it the following captures the principle more perspicuously:

– For all propositions p, if it was the case that p, then p is the case in the past.

Clearly new Growing Blockers will reject this, as Kristie points out, because for some p (e.g. p = Caesar is conscious) it is false, according to their view. She argues they will thus reject the following account of truthmakers:

Past Record Truthmaking (PRT): If past-tensed statement S is true, it is made true by the present-tensed analogue of S, S*, being true in the past.

I agree with all of this. However, I think that PRT is not a particularly perspicuous truthmaker principle. (I take it nothing turns here on the use of ‘statement’ rather than ‘proposition’, so I will stick with the more usual talk of propositions in what follows.)

A truthmaker principle should state what in reality (a fact, or some such) makes a particular proposition true, and although PRT does do this, the fact it appeals to is one that is unlikely to satisfy anyone. In short, PRT says the fact that makes true is: the fact that p is true in the past. But this seems to be, at the very least, a half-way house.

Consider a concrete example, say, . PRT says that this is made true by the fact that is true in the past. But this raises the question: what makes < is true in the past> true? Old Growing Blockers would answer this, presumably, by citing the fact that Caesar exists (in the body of the block) and possesses certain properties (perhaps, if they are physicalists, physical properties of certain sorts). Thus, they will endorse:

1. is made true by the fact that Caesar exists and instantiates various properties.

They would thus offer a unified account of truthmaking because this fact is of the same kind as the facts that make present tense sentences true – for example, they will endorse:

2. is made true by the fact that Kristie exists and instantiates various properties.

Now, new Growing Blockers cannot accept *either* 1 *or* 2. This is because they think that it is not the *mere* possession of properties by things that gives rise to conscious experiences (and so mere facts about objects possessing properties cannot be the truthmakers for propositions about conscious experiences) – rather, it is this together with the undergoing of processes at the edge of the block that does so. In effect, it is the *coming to have* of certain properties that is crucial, and this only takes place at the edge of the block, and not in its body. But once we get clear about this, there seems to be an easy way for them to give a unified account of truthmaking. Consider what they can say about the past-tense proposition above:

1*: is made true by the fact that Caesar exists in the body of the block and possesses certain properties *together* with the fact that our universe is one of becoming.

That Caesar exists in the body of the block and possesses certain properties together with the fact that our universe is one of becoming makes true because it entails that when Caesar’s time was present (i.e. when it was the edge of the block) Caesar was *in the process of coming to have* those properties that he has. But these properties, ex hypothesi, are such that give rise to conscious experiences as they come to be had. (There are some who think all truths have a single truthmaker, but Growing Blockers need not subscribe to this view. So long as there are *facts* about how reality is that ground past truths, I think they meet their truthmaking obligations.)

Now consider what new Growing Blockers can say about present-tense propositions:

2*: is made true by the fact that Kristie exists at the edge of the block and possesses certain properties *together* with the fact that our universe is one of becoming.

That Kristie exists at the edge of the block and possesses certain properties together with the fact that our universe is one of becoming makes true because it entails that Kristie is *in the process of coming to have* properties. But the properties that Kristie is coming to have are again, ex hypothesi, such that give rise to conscious experiences as they *come to be had*.

Compare 1* and 2*. This looks to be a unified account of truthmaking to me. And this is not in any way similar to presentist accounts of truthmaking, and it drops out quite naturally from the Growing Block view. And so new Growing Blockers can give a unified account of truthmakers in the sense mentioned at the start of this post that does not end up being similar to those posited by presentists.

A possibility that Kristie raises later in her paper does offer a problem for the account I’ve just given:

“Plausibly, it is possible for God to create a growing block universe with some of the block “already grown”. To do so would be to create a block universe with slices that are B-related (or quasi- B-related) to one another, and such that that block universe subsequently accretes slices in A-time. Suppose the initial block universe includes all the times up to, and including, the time at which C occurs, as well as the later time at which E occurs. Then the presence of that block does not show that there was ever an A-time at which C was present and E did not exist, despite the fact that the existence of the block makes it true that E does not exist earlier than, or at the same time as, C.” (p27)

In the terms in which I’ve put things, the problem is this: I said the fact that Caesar exists in the body of the block and possesses certain properties together with the fact that our universe is one of becoming makes true because it entails that when the time that Caesar exists at was present Caesar was in the process of coming to have properties. But if becoming is a property of worlds that can be gained or lost (i.e. if there are blocks that grow for a bit, and then stop growing, or blocks that come into existence with a ready formed past, and start growing) then this is not true.

So, if the above account is adopted, it does seem that Growing Blockers must accept that the property of becoming is one that worlds cannot gain or lose. I’m a Humean, so I find such a claim highly suspect, but I see no reason why non-Humeans should balk at this. (And I note that Peter Forrest above seems to be happy with something even stronger than this – that becoming is a *necessary* property of worlds – although he might not put it in terms of properties of worlds). So, I conclude that, contra Kristie, new Growing Blockers can give a unified account of truthmaking in way that does not make their view objectionably close to presentism.

Finally, a brief incidental comment. The account of truthmaking I think new Growing Blockers should adopt, is something like:

– For all propositions p, if it was the case that p, then for some proposition q, q is the case in the past and q (together with the proposition that the world is one of becoming) makes p true.

Kristie

I take it that it is, in some ways, a way of spelling out Peter Forrest’s original view (no the view expressed in his current paper) – though not the way he does spell it out. Because you might think that his original appeal to the way things are in the past, plus the fact that there are later times (i.e. time has moved on) is similar in spirit to the claim that there are ways things are in the past, plus the fact that our world has becoming. But I agree that the way of putting it makes the unity much clearer.

I agree that if you can rule out the “pre-existing” back block, then this looks like it might work.

There’s something puzzling/worrisome about the proposal, that I’m still trying to put my finger on (and i’m not sure if it’s just that as an eternalist I find it unappealing, or if it’s something the GB’er ought to care about).

Here’s a first stab at one thing that seems odd. part of the truth maker is that our world is one of becoming. What makes that true? In particular, at the end of time, when all we have is a 4D block, what make that true? If we have all of the back blocks, existing in hyper-time then we could use those to make this true (perhaps that is the thought?) – but if we just have A-time, then there seems to be no truth maker for that claim (although obviously there was such a truth maker). But if you have all of the back blocks, I’m tempted to use them as truth makers (as per hyper temporal truth making).

There’s something else worrisome about this proposal, but I can’t put my finger on what it is- so I will go off and think about it some more!

I should say that I share your feelings that there is something worrisome about the proposal – I was thinking it was my Humeanism that was giving rise to my worries (i.e. because it relies on the property of becoming being one that cannot be gained or last by a world, and as a Humean I say that this is to posit an illegitimate necessary connection between the world and the property), but there is still a lingering doubt that there’s something more.

You ask: what makes it true that a world is one that possesses becoming? I’m not sure I see the concern here, I’m afraid (but I might be missing something). Isn’t it just a straightforward case of property possession? If we ask what makes it true that Smith is tall, we can answer simply by saying that it is the fact that Smith exists and possesses the property of being tall. So why can’t the growing blocker simply say in this case that the world exists and possesses the property of becoming? Why should they need anything else as a truthmaker?

You also ask: In particular, at the end of time, when all we have is a 4D block, what make that true? As I said above, I was thinking that growing blockers must think that the property of becoming is one that cannot be lost by a world, so they will have to deny the possibility of a world in which there is an end of time. Again, for me as a Humean, this is an unsatisfactory thing to say – like in all other cases, a commitment to necessary connections here leads to the denial of something that Humeans believe is clearly a possibility (hence the link between the denial of necessary connections and the Humean principle of recombination that governs what possibilities there are). But those without Humean scruples don’t worry too much about denying such possibilities.

Now, I admit that the property of becoming is itself an odd property, and there might be something about it that is suspect, but it seems to be a property that growing blockers must believe in anyway, and so is not an additional ad hoc commitment. The additional element is the notion that it cannot be gained or lost by worlds (it is, if you like, an essential property of those worlds that possess it). But I was thinking here, in particular, that by believing that the property is possessed essentially by worlds growing blockers do *not* have to believe in the existence of back blocks in hypertime. That there *were* previous hypertimes (even though there are not now any) and even *what* hypertimes there were is entailed by the facts about the state of the block now and the fact that the world is one that possesses (essentially) the property of becoming. So this view is consistent with hypertime presentism, which seems to me to be an advantage.

At any rate, this is how I *think* things stand for the growing blocker who adopts this position. But, as I said, there is also a nagging doubt that there is something suspicious about all of this aside from its anti-Humean commitments, but if there is, it’s something I can’t put my finger on either!

“part of the truth maker is that our world is one of becoming. What makes it true?”

Is this not something that laws can do for us? If we believe there is some irreducible modility on the Growing-Block view, this can constrain how the future evolves. But it can also dictate that the future becomes. The laws (for Rachael and I) determine whether something is an incomplete, semi-complete or complete timeline. If it’s an incomplete timeline, the laws dicate that the block has to grow.

Whatever makes the laws true, makes it true that it is a world of becoming. As long as you are a realist about fundamental modality, the problem doesn’t seem to arise.

[NB I’m reposting my above comment as I used the normal angle brackets around propositions, which was messed up by the html tagging. I’ve not put propositions in square brackets, and hopefully it will work.]

Peter Forrest’s comments above are interesting, but I shan’t engage with them here as I plan to read his paper shortly and so will save any comments I have for then. I wish, rather, to pick up on a slightly different issue arising from Kristie’s (also very interesting) paper.

The issue I wish to pick up on is the issue of whether Growing Block theorists can offer a unified approach to truthmaking that does not end up being similar to those posited by presentists (that they cannot is one horn of a dilemma that Kristie poses in her paper). Here I respond to her by arguing that they can.
Firstly, what is it to offer a ‘unified’ account of truthmaking? Kristie says:

“an approach to truthmaking is unified just in case the sorts of truthmakers it posits for present-tensed statements are the same as the sorts of truthmakers it posits for past-tensed statements.” (p10)

Kristie argues that Growing Blockers cannot offer such an account. She starts by considering a principle from Cameron (2015):

Past Record (PR): If something was the case, then it is the case in the past.

This is supposed to be read as a universally quantified claim, and given the (anaphoric) occurrence of ‘it’ in the consequent, I take it the following captures the principle more perspicuously:

– For all propositions p, if it was the case that p, then p is the case in the past.

Clearly new Growing Blockers will reject this, as Kristie points out, because for some p (e.g. p = Caesar is conscious) it is false, according to their view. She argues they will thus reject the following account of truthmakers:

Past Record Truthmaking (PRT): If past-tensed statement S is true, it is made true by the present-tensed analogue of S, S*, being true in the past.

I agree with all of this. However, I think that PRT is not a particularly perspicuous truthmaker principle. (I take it nothing turns here on the use of ‘statement’ rather than ‘proposition’, so I will stick with the more usual talk of propositions in what follows.)

A truthmaker principle should state what in reality (a fact, or some such) makes a particular proposition true, and although PRT does do this, the fact it appeals to is one that is unlikely to satisfy anyone. In short, PRT says the fact that makes [it was the case that p] true is: the fact that p is true in the past. But this seems to be, at the very least, a half-way house.

Consider a concrete example, say, [it was the case that Caesar is conscious]. PRT says that this is made true by the fact that [Caesar is conscious] is true in the past. But this raises the question: what makes [[Caesar is conscious] is true in the past] true? Old Growing Blockers would answer this, presumably, by citing the fact that Caesar exists (in the body of the block) and possesses certain properties (perhaps, if they are physicalists, physical properties of certain sorts). Thus, they will endorse:

1. [It was the case that Caesar is conscious] is made true by the fact that Caesar exists and instantiates various properties.

They would thus offer a unified account of truthmaking because this fact is of the same kind as the facts that make present tense sentences true – for example, they will endorse:

2. [It is the case that Kristie is conscious] is made true by the fact that Kristie exists and instantiates various properties.

Now, new Growing Blockers cannot accept *either* 1 *or* 2. This is because they think that it is not the *mere* possession of properties by things that gives rise to conscious experiences (and so mere facts about objects possessing properties cannot be the truthmakers for propositions about conscious experiences) – rather, it is this together with the undergoing of processes at the edge of the block that does so. In effect, it is the *coming to have* of certain properties that is crucial, and this only takes place at the edge of the block, and not in its body. But once we get clear about this, there seems to be an easy way for them to give a unified account of truthmaking. Consider what they can say about the past-tense proposition above:

1*: [It was the case that Caesar is conscious] is made true by the fact that Caesar exists in the body of the block and possesses certain properties *together* with the fact that our universe is one of becoming.

That Caesar exists in the body of the block and possesses certain properties together with the fact that our universe is one of becoming makes [it was the case that Caesar is conscious] true because it entails that when Caesar’s time was present (i.e. when it was the edge of the block) Caesar was *in the process of coming to have* those properties that he has. But these properties, ex hypothesi, are such that give rise to conscious experiences as they come to be had. (There are some who think all truths have a single truthmaker, but Growing Blockers need not subscribe to this view. So long as there are *facts* about how reality is that ground past truths, I think they meet their truthmaking obligations.)

Now consider what new Growing Blockers can say about present-tense propositions:

2*: [It is the case that Kristie is conscious] is made true by the fact that Kristie exists at the edge of the block and possesses certain properties *together* with the fact that our universe is one of becoming.

That Kristie exists at the edge of the block and possesses certain properties together with the fact that our universe is one of becoming makes [it is the case that Kristie is conscious] true because it entails that Kristie is *in the process of coming to have* properties. But the properties that Kristie is coming to have are again, ex hypothesi, such that give rise to conscious experiences as they *come to be had*.

Compare 1* and 2*. This looks to be a unified account of truthmaking to me. And this is not in any way similar to presentist accounts of truthmaking, and it drops out quite naturally from the Growing Block view. And so new Growing Blockers can give a unified account of truthmakers in the sense mentioned at the start of this post that does not end up being similar to those posited by presentists.

A possibility that Kristie raises later in her paper does offer a problem for the account I’ve just given:

“Plausibly, it is possible for God to create a growing block universe with some of the block “already grown”. To do so would be to create a block universe with slices that are B-related (or quasi- B-related) to one another, and such that that block universe subsequently accretes slices in A-time. Suppose the initial block universe includes all the times up to, and including, the time at which C occurs, as well as the later time at which E occurs. Then the presence of that block does not show that there was ever an A-time at which C was present and E did not exist, despite the fact that the existence of the block makes it true that E does not exist earlier than, or at the same time as, C.” (p27)

In the terms in which I’ve put things, the problem is this: I said the fact that Caesar exists in the body of the block and possesses certain properties together with the fact that our universe is one of becoming makes [it was the case that Caesar is conscious] true because it entails that when the time that Caesar exists at was present Caesar was in the process of coming to have properties. But if becoming is a property of worlds that can be gained or lost (i.e. if there are blocks that grow for a bit, and then stop growing, or blocks that come into existence with a ready formed past, and start growing) then this is not true.

So, if the above account is adopted, it does seem that Growing Blockers must accept that the property of becoming is one that worlds cannot gain or lose. I’m a Humean, so I find such a claim highly suspect, but I see no reason why non-Humeans should balk at this. (And I note that Peter Forrest above seems to be happy with something even stronger than this – that becoming is a *necessary* property of worlds – although he might not put it in terms of properties of worlds). So, I conclude that, contra Kristie, new Growing Blockers can give a unified account of truthmaking in way that does not make their view objectionably close to presentism.

Finally, a brief incidental comment. The account of truthmaking I think new Growing Blockers should adopt, is something like:

– For all propositions p, if it was the case that p, then for some proposition q, q is the case in the past and q (together with the proposition that the world is one of becoming) makes p true.

Natalja

Clarificatory question on p. 5: Is Cameron saying that in a presentist world, one can’t rule out whether there are non-present times (why not)?

p. 12 onwards: I’m not sure how the question of truth-makers bears on (II). E.g. in the case of the Past Record view, it certainly doesn’t give one a new reason to think that there is a difference between how things seemed to Sam when he was objectively present, and how they seem to him in the past. But why does it give one a reason to think there is no difference? Similarly, in the case of the hyper-temporal Record view, why does it give one a reason to think there is a difference?

Again, in the case of the TDP Present Record view, I’m not sure what’s doing the work (for suggesting that (II) is false on this view) – it’s something about how ‘Caesar is conscious’ is made false and ‘Caesar was conscious’ is made true. Namely, via the claim that how things are now is how things are simpliciter, and in particular that Caesar has a certain TDP, an age, essential properties that don’t include conciousness, and no other properties. But I’m not sure what it is about a TDP that bears on how being in the objective past seems introspectively compared to being in the objective present. He has the TDP now; and it describes him as having lacked consciousness. But how is that relevant, other than to the (thereby secured) truth of ‘Caesar was conscious’ and falsity of ‘Caesar is conscious’, which the Past Record view secures too? Is the idea that on the Past Record view things exist in a uniform atemporal state of being, which colours all their perceptions equally no matter which time they are at? Must this be a part of the Past Record view though?

About the TDP view: if all that’s the case is what’s the case now, not what was or will be, how can there be facts about how objects were and will be, and how can there be non-present things?
p. 17 So a TDP mentions itself, saying that it was and will be the same as it is now? So there can be TDP’s about the future, just not about future objects?

About the Hyper-temporal view: so the view involves three time-like dimensions, one B-theoretic quasi-time, A-time, and hyper-time, which also seems B-theoretic (unless a-temporal time is different still)? I’m then not sure what work A-times are doing, or how they can exist at hyper-times. E.g. on p.14, if slices of back blocks are identified, why does that mean ‘that the very same moment in A-time exists at multiple hyper-times’, as opposed to just that the same B-theoretic slice exists at multiple hyper-times?

Might there be room for a disunified view that takes Hyper-time to provide truthmakers for past tensed truths, but the back-block (of this A-time) to provide truthmakers for present tensed truths?

Kristie

Answer to classificatory question: yes, I think he is saying that. I think the idea is this: you can’t be sure you ARE in a presentist world, even if you are. So you can’t be sure there aren’t non-present times (because if you are in fact in an eternalist world, then there are). but you can’t know a priori that you are in a presentist world, so you can’t rule out that there are,in fact, non-present times.

Re first worry. (I might be misreading the question here – if so apologies) – Re the hyper-temporal view first. Yes, I agree it doesn’t give you reason to think the experiences are different (PF also points this out). Rather, the idea is just that IF they are different, we can still get the truth of ‘caesar was conscious’ by appealing to a conscious caesar even though there is also an Unconscious caesar. But as you note, the view is perfectly compatible with thinking that there are only conscious caesars because there is no difference between past caesar and present caesar. The thought was just that there is a way of making ‘caesar was conscious’ come out true, by taking you a time in A-time when he is conscious (even though he isn’t conscious in the past). I think that was unclear.

Re the past record case. Does that give us a reason to think the experiences are the same? No, again you’re right. Rather, the thought is that if they are different then we won’t have any truth maker at all for ‘caesar was conscious’ there is nowhere to be found, a conscious caesar. But if they are the same, then although we get the truth maker stuff to work, we can’t solve the now now problem.

I think that it was unclear that the truth maker principles aren’t supposed to give you reason to think that caesar is, or is not, different (or the same) in the past. They’re just supposed to tell you what follows given that he is, or is not, different.

Re the TDP case. I think in this case it IS supposed to follow that he is different ‘in the past’. I find this view pulling, so I’m not the best guide to it (hence don’t let me lead you astray) – but as I understand it, it follows from the fact that what is true, simpliciter, is what is true as of now. Since as of now, Caesar has no mass, it follows that it has no mass, simpliciter. Since that it the total truth, – there are no further truths about the past – it follows that he must be different, in the past, than he was (since it was once true that he did have a mass). As to how things seem, in the past, to Caesar. I have no idea! The claim is meant to be that they don’t seem any way at all, because the way things are, now, is the way they are simpliciter, and the way they are now, is that caesar is not conscious. So I take it there is no way things are, from the perspective of the objective past.

Re the TDP view and non-present things. Cameron is defending the moving spotlight view, so he thinks there are future things (and future TDPs) – but obviously a GBer will need to amend this somewhat (open question how best to do this). How are there non-present things if everything is true, simpliciter, is what is true now? So I think the idea is that an object – say Freddie, has properties like this: at DATE, I am curly, at Date1, I am straight, at Date2, I am wet (Freddie is a dog) etc. He has all these properties at all times he exists – they specify how Freddie is, across time, for all time (assuming the MS view). So, suppose today is Date 1. Then Freddie’s Date1 property says that he is, simpliciter, straight (since it is presently Date1). But his properties also say that the WAS curly – because he has the property of being curly at DATE. So his present state, makes true the past-tensed claim about him having been curly, even though he is straight, simpliciter.

Now suppose it is DATE 39, and Freddie is no longer with us – he has gone to the rainbow bridge. What are his TDPS? Well there is no Freddie in the present (the only relevant time) – so Freddie doesn’t have the property of being curly, or straight, or conscious. He did have those properties – he exists back these in the past, and he has the TDPS back in the past, and that’s what makes the past-tensed stuff true.

Re the hyper-temporal view. Good question – how do the three time-like dimensions interact? So I was thinking, roughly that the A-time is the coming into existence of new slices, and the objective presentness of the end slice. So suppose time travel is possible, and one effectively travels in hyper-time – always arriving at the relevant time when it is the objective present (in A-time). In some good sense it looks as though one is travelling back to a “different” back block any time one travels (depending on how you individuate these). Suppose (given that there is HT) one can change the past in the following sense: one can make something happen at the objective present which, in other back blocks that still exist in HT, did not happen. (this is not really changing the past of course, but it’s doing something). Then although relative to some previous HT, X occurred at A-time T(when T is the objective past relative to that HT), relative to this new HT, X does not occur at A-time T. Relative to this HT there is a consistent A-series, and at the relevant time, X does not occur.

I’m thinking that this s the way the three temporal dimensions “come apart”. So long as there is no time travel though, the A-times and the hyper-times will go in tandem.

Re last question: so is the idea that ‘caesar is a zombie’ will be made true by the back block of the A-time, but ‘caesar was conscious’ is made true by the hyper-time at which caesar is present? Yes, I think you could have that view (and indeed, I think that would be sensible given hyper-temporal truth making.

Natalja

Answer to classificatory question: yes, I think he is saying that. I think the idea is this: you can’t be sure you ARE in a presentist world, even if you are. So you can’t be sure there aren’t non-present times (because if you are in fact in an eternalist world, then there are). but you can’t know a priori that you are in a presentist world, so you can’t rule out that there are,in fact, non-present times.

Right. But then I don’t think that establishes that presentism is no better off. Assuming internalism, he’s saying since you can’t rule out you’re in a non-presentist world you can’t know you’re in a presentist world. Hence even if you are you can’t know you’re not objectively past.
Suppose the relevant non-ruled out alternative is eternalism; surely that alternative shouldn’t threaten your knowledge that you’re not objectively past, since on that alternative there is no objective past. Maybe it threatens your knowledge that you’re objectively present, but only because there might be none. If the relevant alternative is the GB view, then whether or not that threatens your knowledge depends on the merits of (this version of) the now now objection. If the objection holds, the problem for presentism is derivative (and maybe it holds for eternalism too?).
Surely the problem is that even if you could know the true metaphysics of time, if that was the GB view, you still wouldn’t know you’re in the objective present (and not the objective past).

Re first worry. (I might be misreading the question here – if so apologies) – Re the hyper-temporal view first. Yes, I agree it doesn’t give you reason to think the experiences are different (PF also points this out). Rather, the idea is just that IF they are different, we can still get the truth of ‘caesar was conscious’ by appealing to a conscious caesar even though there is also an Unconscious caesar. But as you note, the view is perfectly compatible with thinking that there are only conscious caesars because there is no difference between past caesar and present caesar. The thought was just that there is a way of making ‘caesar was conscious’ come out true, by taking you a time in A-time when he is conscious (even though he isn’t conscious in the past). I think that was unclear.

Sorry, I think I was being sloppy. What I meant to ask was how the view gives one freedom to reject (II). I took the idea to be that it gives one that freedom, because it allows one to do it while still making past-tensed truths true. Whereas the Past Record view (provided it makes all the past-tensed truths true) doesn’t give one that freedom, because the way it makes those past-tensed truths true forces an acceptance of (II). But that’s what I don’t see.
Take the Past Record view. If it really says what a block theorist says (about past times), I don’t see how it bears on how (or whether) things seem introspectively, to anyone. That is, if the view basically says that past-tensed statements are made true by its being atemporally the case that Caesar is conscious at t0, then I don’t see how that bears on how (or whether) things seem to Caesar ‘in the past’. Now of course, that’s not exactly what the view says. Maybe it’s only what allows the block theorist to accept Past Record. But then I wonder what would happen if the growing block theorist just said about the past what the block theorist says. I also wonder how to understand Past Record view (and perhaps (II) too). What is it for something to be true in the past (on this view), if not for it to be atemporally true at a time earlier than the present?
The general idea, I take it, is that rejecting (II) involves positing a varied block, with the edge unconscious and the back block conscious. So to still get ‘Caesar was conscious’ we have to go to hyper-time, not just the back block. But what rejecting (II) involves depends on what the objective present and past are, and it seems a bit as if what these are depends on what makes past-tensed truths true. E.g. on the Hyper-temporal Record view, why think an unconscious Caesar in the back block makes for a different (or non-) seeming objective past, when he’s irrelevant to which past-tensed truths are true?

Re the hyper-temporal view. Good question – how do the three time-like dimensions interact? So I was thinking, roughly that the A-time is the coming into existence of new slices, and the objective presentness of the end slice. So suppose time travel is possible, and one effectively travels in hyper-time – always arriving at the relevant time when it is the objective present (in A-time). In some good sense it looks as though one is travelling back to a “different” back block any time one travels (depending on how you individuate these). Suppose (given that there is HT) one can change the past in the following sense: one can make something happen at the objective present which, in other back blocks that still exist in HT, did not happen. (this is not really changing the past of course, but it’s doing something). Then although relative to some previous HT, X occurred at A-time T(when T is the objective past relative to that HT), relative to this new HT, X does not occur at A-time T. Relative to this HT there is a consistent A-series, and at the relevant time, X does not occur.
I’m thinking that this s the way the three temporal dimensions “come apart”. So long as there is no time travel though, the A-times and the hyper-times will go in tandem.

I think I may have to understand how they differ in general before I can try to understand the time travel case. I’m still stuck at ‘so that the very same moment…’ (p. 14). Either way (whether we identify quasi-B-slices across hyper-times or not), I’m picturing a hyper-time line, at each of which there is a block of increasing length, where the last slice of each block either itself is, or corresponds to, the A-time corresponding to that hyper-time. Now suppose slices endure in hyper-time (i.e. we do identify). Why does that mean the very same moment in A-time – i.e. the very same A-moment, the very same A-time (?) – exists at multiple hyper-times? Perhaps because the last slice of each block IS an A-time (as well as a quasi-B-time). So I take it the reason this means that a given A-time doesn’t stay in (why in?) the objective present over hyper-time is that the slice it is doesn’t stay the latest slice. But then I’ve lost my grip on the original picture, in which the A-times were (or corresponded to) the latest slices of the blocks. What makes the A-times we have now, A-times? Each seems to be present only at one hyper-time, rather like a quasi-B-time (unsurprisingly).
So that suggests that the last slices aren’t themselves A-times but only correspond to them. What’s the correspondence rule? Does each correspond to the same A-time across hyper-time?

Re last question: so is the idea that ‘caesar is a zombie’ will be made true by the back block of the A-time, but ‘caesar was conscious’ is made true by the hyper-time at which caesar is present? Yes, I think you could have that view (and indeed, I think that would be sensible given hyper-temporal truth making.

Sorry my mistake again, not back block, but edge of block: I meant, a view on which Hyper-time provides truthmakers for past tensed truths, but the block, i.e. its edge, provides truthmakers for present tensed truths. I take it that would be different from the above, which is just the Hyper-temporal Record view. It would be disunified. Ah but it’s only a different view if I’ve understood the Hyper-temporal Record correctly when I supposed that we’re not identifying block edges with A-times…

Peter Forrest

Thanks Ben.Yopu say ‘And I note that Peter Forrest above seems to be happy with something even stronger than this – that becoming is a *necessary* property of worlds – although he might not put it in terms of properties of worlds). ‘

I think of the passage of time as growth of the unordered block wrt the ordinal sequence of (hyper-)times). I did say that this sequence was metaphysically necessary but I now think that’s a mistake. If it starts at 1 it could have stopped there and at each stage it could stop. That hypertime goes on and that the block grows rather than shrinks depends, I think, on there being further observations and acts, but that is another story.